Definitions of Animal Feeding Operation (AFO) and Concentrated Animal Feeding Operation (CAFO)
Animal Feeding Operation (501.225) –
(a) A lot or facility (other than an aquatic animal production facility) where the following
conditions are met:
(1) Animals have been, are or will be stabled or confined and fed or maintained for a total
of 45 days or more in any 12-month period, and
(2) Crops, vegetation, forage growth or post-harvest residues that are grown in place are
not sustained in the normal growing season over any portion of the lot or facility.
(b) Two or more animal feeding operations under common ownership are deemed to be a
single animal feeding operation if they are adjacent to each other or if they utilize a
common area or system for the disposal of wastes.
Concentrated Animal Feeding Operation (CAFO) (501.238) – An Animal Feeding Operation (AFO) that is
defined as a Large CAFO pursuant to 35 Ill. Adm. Code 502.103 or as a Medium CAFO pursuant to 35 Ill.
Adm. Code 502.104, or that is designated as a CAFO pursuant to 35 Ill. Adm. Code 502.106.
Large CAFO (502.103) – An AFO is defined as a large CAFO if at least the numbers of animals specified in
any of the following categories are stabled or confined:
700
1,000
1,000
2,500
10,000
500
10,000
55,000
30,000
125,000
82,000
30,000
5,000
Mature dairy cows, whether milked or dry
Veal calves
Cattle other than mature dairy cows or veal calves. Cattle includes but is not
limited to heifers, steers, bulls and cow/calf pairs.
Swine, each weighing 55 pounds or more
Swine, each weighing less than 55 pounds
Horses
Sheep or lambs
Turkeys
Laying hens or broilers, if the Animal Feeding Operation uses a liquid manure
handling system
Chickens (other than laying hens), if the Animal Feeding Operation uses other
than a liquid manure handling system
Laying hens, if the Animal Feeding Operation uses other than a liquid manure
handling system
Ducks, if the Animal Feeding Operation uses other than a liquid manure
handling system
Ducks, if the Animal Feeding Operation uses a liquid manure handling system
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Medium CAFO (502.104) – An AFO is defined as a medium CAFO if at least the following numbers of
animals specified in any of the following categories are stabled or confined and the provisions of
subsection (b), (c) or (d) of this Section is met:
200 to 699
300 to 999
300 to 999
Mature dairy cows, whether milked or dry
Veal calves
Cattle other than mature dairy cows or veal calves. Cattle includes but is
not limited to heifers, steers, bulls and cow/calf pairs
750 to 2,499
Swine, each weighing 55 pounds or more
3,000 to 9,999
Swine, each weighing less than 55 pounds
150 to 499
Horses
3,000 to 9,999
Sheep or lambs
16,500 to 54,999
Turkeys
9,000 to 29,999
Laying hens or broilers, if the Animal Feeding Operation uses a liquid
manure handling system
37,500 to 124,999
Chickens (other than laying hens), if the Animal Feeding Operation uses
other than a liquid manure handling system
25,000 to 81,999
Laying hens, if the Animal Feeding Operation uses other than a liquid
manure handling system
10,000 to 29,999
Ducks, if the Animal Feeding Operation uses other than a liquid
manure handling system
1,500 to 4,999
Ducks, if the Animal Feeding Operation uses a liquid manure
handling system
b) Pollutants are discharged into waters of the United States through a man-made ditch, flushing system
or other similar man-made device; or
c) Pollutants are discharged directly into waters of the United States that originate outside of and pass
over, across, through or otherwise come into direct contact with the animals confined in the operation;
or.
d) The Animal Feeding Operation is designated as a CAFO by the Agency pursuant to Section 502.106.
Small CAFO - An Animal Feeding Operation is a Small CAFO if it is designated as a CAFO by the Agency
pursuant to Section 502.106, and it is not a Medium CAFO.
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